Which of the following brain waveforms are present during wakefulness? 1. Alpha waves 2. Beta waves 3. Relatively low-voltage, mixed-frequency waves 4. Delta waves

a. 1 and 2 c. 3 and 4
b. 2 and 3 d. 1, 2, and 4

ANS: A
An electroencephalogram shows that alpha waves and beta waves are present during wakefulness and diminish as the sleeper's electroencephalogram converts to relatively low-voltage, mixed-frequency waves. Delta waves are present during slow-wave sleep or the deepest stages of non-REM sleep.